18. Ryan says that he thinks the weather will be getting colder over the next few days because a cold front is approaching. What is the best way to verify this prediction?

A. Use a barometer and thermometer to record the air pressure and temperature for 5 days.
B. Record the air pressure and temperature every hour for the next 24 hours.
C. Observe carefully to see if any thunderstorms occur over the next few days.
D. Go online to determine the temperature and air pressure for the past 5 days.